Drive system for a railway hopper car discharge gate

Abstract

A drive system for a railway hopper car discharge gate includes a door panel operated by a rack and pinion drive. The pinion teeth present a substantially cylindrical profile in a plane orthogonal to the axis of pinion rotation. The cylindrical tooth profile substantially prevents the pinion teeth from skipping or walking against the rack teeth when the spacing between the pinion and the door panel and associated rack fluctuates during operation of the discharge gate. Pinion torque is converted into a vertical force at the ends of travel of the door panel to prevent damage to the drive components. A bearing arrangement supports a drive shaft that is operated to rotate the pinions, and minimizes deflection of the shaft when under rotational load. An inertia brake is provided to engage the door panel and prevent it from opening upon a rapid stop of the hopper car as may occur upon impact with an adjacent railway car.

1. A drive system in combination with a railroad car discharge gate, comprising:
 a hopper frame defining a discharge opening, 
 a door panel movable along a fore and aft path across said opening and between an open position and a closed position, 
 a rack attached to said door panel and extending along said path, said rack presenting multiple rack teeth, 
 a drive shaft associated with said hopper frame, extending transversely of said path, and having an outer end adapted to be coupled with an operating device, 
 a gear mounted on said shaft for rotation thereby and having a plurality of gear teeth successively engageable with said rack teeth, 
 an elongated, tubular spacer receiving said shaft between said gear and said outer end for supporting said shaft against deflection under rotational load, 
 said spacer having an inner end adjacent said gear and being provided with structure at said inner end restraining said spacer against radial movement, and 
 a bearing tube generally coaxial with said spacer and fixed to said hopper frame. 
 
   
   
     2. The drive system of  claim 1 , wherein said structure comprises a bearing engageable with said tube. 
   
   
     3. The drive system of  claim 1 , wherein each of said gear teeth presents a substantially semicircular working surface, said rack having teeth of constant pitch. 
   
   
     4. The drive system of  claim 1 , wherein each of said gear teeth presents a substantially cylindrical profile in a plane orthogonal to an axis of gear rotation. 
   
   
     5. The drive system of  claim 1 , wherein said door panel is generally horizontal, said system further comprising an inertia brake for holding said door panel against forward movement, said brake including a counterweight above said door panel having a braking position and a released position, an arm mounting said counterweight for movement between said braking position and said released position in response to normal opening of said door panel, and structure on said arm for engaging and holding said door panel when the counterweight is in its braking position and responds to a forward force indicative of a rapid halt of the car. 
   
   
     6. A drive system in combination with a railroad car discharge gate, comprising:
 a hopper frame defining a central opening, 
 a generally horizontal door panel movable alone a fore and aft path across said opening and between an open position and a closed position, 
 a rack attached to said door panel and extending along said path, said rack presenting multiple rack teeth of constant pitch, 
 a drive shaft associated with said hopper frame, extending transversely of said path, and having an outer end adapted to be coupled with an operating device, 
 a gear mounted on said shaft and having a plurality of gear teeth in meshed engagement with said rack, each of said gear teeth presenting a cylindrical profile in a plane orthogonal to an axis of rotation of said gear, and 
 an inertia brake for holding said door panel against forward movement, said brake including a counterweight above said door panel having a braking position and a released position, an arm mounting said counterweight for movement between said braking position and said released position in response to normal opening of said door panel, and structure on said arm for engaging and holding said door panel when the counterweight is in its braking position and responds to a forward force indicative of a rapid halt of the car. 
 
   
   
     7. A chive system in combination with a railroad car discharge gate, comprising:
 a hopper frame defining a central opening, 
 a generally horizontal door panel movable along a fore and aft path across said opening and between an open position and a closed position, 
 a rack attached to said door panel and extending along said path, said rack presenting multiple rack teeth, 
 a drive shaft associated with said hopper frame, extending transversely of said path, and having an outer end adapted to be coupled with an operating device, 
 a gear mounted on said shaft for rotation thereby and having a plurality of gear teeth successively engageable with said rack teeth, and 
 an inertia brake for holding said door panel against forward movement, said brake including a counterweight above said door panel having a braking system and a released position, an arm mounting said counterweight for movement between said braking position and said released position in response to normal opening of said door panel, and structure on said arm for engaging and holding said door panel when the counterweight is in its braking position and responds to a forward force indicative of a rapid halt of the car. 
 
   
   
     8. The drive system of  claim 7 , wherein said structure includes a strike element for engaging a leading edge of said door panel. 
   
   
     9. The drive system of  claim 7 , wherein said inertia brake further includes a yieldable component biasing said arm to return the counterweight to its braking position after said panel is opened and closed. 
   
   
     10. A drive system in combination with a railroad car discharge gate, comprising:
 a hopper frame defining a central opening, 
 a generally horizontal door panel movable along a fore and aft path across said opening and between an open position and a closed position, 
 a rack attached to said door panel and extending along said path, said rack presenting multiple rack teeth terminating at an end of the rack, 
 a drive shaft associated with said hopper frame, extending transversely of said path, and having an outer end adapted to be coupled with an operating device, 
 a gear mounted on said shaft for rotation thereby and having a plurality of gear teeth successively engageable with said rack teeth, 
 a stop on said panel adjacent said end of the rack, engageable by said gear and cooperating therewith to convert torque applied to said stop by said gear to a generally vertical force applied to said panel, and 
 structure engageable with said panel for providing a counterforce in response to said applied force. 
 
   
   
     11. The drive system of  claim 10 , wherein each of said gear teeth presents a cylindrical profile in a plane orthogonal to an axis of rotation of said gear. 
   
   
     12. A drive system in combination with a railroad car discharge gate, comprising:
 a hopper frame defining a central opening, 
 a generally horizontal door panel movable along a fore and aft path across said opening and between an open position and a closed position, 
 a rack attached to said door panel and extending along said path, said rack presenting multiple rack teeth terminating at an end of the rack, 
 a drive shaft associated with said hopper frame, extending transversely of said path, and having an outer end adapted to be coupled with an operating device, 
 a gear mounted on said shaft and having a plurality of gear teeth in meshed engagement with said rack, each of said gear teeth presenting a cylindrical profile in a plane orthogonal to an axis of rotation of said gear, 
 a stop on said panel adjacent said end of the rack, engageable by said gear and cooperating therewith to convert torque applied to said stop by said gear to a generally vertical force applied to said panel, 
 structure engageable with said panel for providing a counterforce in response to said applied force, 
 an elongated, tubular spacer receiving said shaft between said gear and said outer end for supporting said shaft against deflection under rotational load, and 
 an inertia brake for holding said door panel against forward movement, said brake including a counterweight above said door panel having a braking position and a released position, an arm mounting said counterweight for movement between said braking position and said released position in response to normal opening of said door panel, and structure on said arm for engaging and holding said door panel when the counterweight is in its braking position and responds to a forward force indicative of a rapid halt of the car.